Studies of somatostatin and cortisol in relation to affective and other neuropsychiatric disorders have continued. Findings consist of the follow- ing. A) Somatostatin - Almost identical significant correlations have been demonstrated between CSF somatostatin and CSF CRH in a wide range of psychiatric disorders (n = 180) and controls (n = 55). No significant difference in CSF somatostatin levels was observed in patients with chronic fatigue syndrome compared with controls. CSF somatostatin was found to be significantly correlated with measures of depression and memory impairment in patients with Alzheimer's disease. CSF somatostatin was significantly correlated with 5-HIAA in depressed Alzheimer's patients and in children with conduct disorder. Longitudinal measurement of CSF somatostatin in 15 patients with chronic progressive multiple sclerosis revealed levels that were significantly lower than those obtained in eight normal subjects; however, no direct relationship between somatostatin levels and cognitive performance was noted. Post-mortem somatostatin concentrations in the prefrontal cortex, amygdala and caudate nucleus did not differ among schizophrenic patients, affective disorder patients, and accident victims. B) Cortisol - While a significant difference was not observed in hourly salivary cortisol samples obtained during the evening in depressed patients compared with controls, a marked exaggeration of the circadian rhythm (significantly higher peaks) of salivary cortisol was observed in depressed patients relative to euthymic patients and controls.